Set Appliance State:

Mains Power Off
Gas Off
Turn Hot Water Tap On
Mode Selector Switch to DHW position
WARNING! Mains voltage is expected during test, follow TOPs P4 live testing procedure
Mains Power On

Observation:

After fan has started, can sparking be seen/heard from Spark Electrode?
Note:
Sparking will only continue for approximately 10 seconds before boiler goes to lockout.
Turn selector switch to reset/lockout after test.